The present invention relates to a jig type treatment apparatus and more particularly to a jig type textile dyeing apparatus. The apparatus incorporates an axially oscillating roller for staggered winding and unwinding of a fabric web. A self lubricating and self aligning bearing assembly adapted for use in supporting relation along the oscillating roller and other cooperating rollers is also provided. The jig type dyeing apparatus of the present invention is particularly well suited to high temperature pressurized dyeing applications treating large rolls of fabric although it is likewise suitable for other bath treatment procedures including bleaching, soaping, and the like.
A jig operates by rolling out a piece of rolled-up fabric disposed around a first roller and causing the fabric to pass through a heated treatment bath such as a dye bath or the like and collecting the treated fabric on a second cooperating roller. Once the fabric has been passed through the treatment bath and collected on the second roller, the travel direction is reversed so that the fabric is built up again on the first roller with the fabric continuing to pass through the treatment bath. The jig typically has various control members to carry out functions during the treatment such as reversing the direction of rotation of the rollers, stopping operation after a predefined selected number of passes, regulating the speed of the rollers, regulating the tension of the fabric and the like.
A general benefit of a jig type treatment system resides in the ability to treat large quantities of fabric using a relatively small volume of bath solution thus providing substantial savings in water and energy. Moreover, due to the ability to carry out as many or as few exposure cycles as desired, the overall level of treatment may be varied as desired thereby providing the user with a substantial degree of freedom in the treatment process.
While traditional jig type dyeing machines have proven to be highly useful they have nonetheless faced certain difficulties arising from the closed environment of treatment and relatively little space available therein. One problem which has been identified in the past arises from the general construction of the fabrics which are treated. In particular, woven fabrics are typically formed with some of type of finished edge extending in the length dimension of the fabric along both sides of the fabric. Such finished edges are utilized to promote the integrity of the formed fabric so as to prevent an unraveling of the yarns forming the fabric along the edges. As will be appreciated, the finished edges give rise to a very slight increase in thickness at the edge. While the increased thickness is not generally noticeable when the fabric is in a flat condition, when the fabric is arranged into a multi-layer roll form the increased thickness along the edges may give rise to a pronounced variation in roll thickness between the edge of the roll and the interior portion of the roll. The fabric roll may thereby take on a so called xe2x80x9cdog bonexe2x80x9d geometry along its length. This dog bone geometry becomes more pronounced as the size of the fabric roll is increased and correspondingly is diminished as the size of the roll is decreased. Thus, in a jig type treatment apparatus the shape of the fabric rolls may vary substantially during different stages of treatment as the fabric is passed from one roller to the other. In extreme circumstances, this variation in the geometry may negatively influence the uniformity of exposure of the fabric web to the treatment bath during the treatment cycle and may thereby influence the uniformity of final coloration.
Aside from the difficulties arising from the variations in roll profile the actual environment of the treatment apparatus may give rise to difficulties in maintaining a substantially smooth winding and unwinding of the fabric between the rollers. In particular, the rollers which carry the fabric must be rotated in a lubricated environment so as to substantially avoid any irregularity in rotation. However, due to the closed high temperature environment of operation, it is difficult to deliver appropriate lubrication to the rotating roll elements without undue complexity. Moreover, difficulties in maintaining lubrication may arise due to wear and/or displacement which impact the position of the roller shaft during operation over the life of the jig.
According to one aspect of the invention, a jig dyeing machine is provided which is adapted for use in either atmospheric or high pressure/temperature conditions and which incorporates at least one axially displaceable roller for supporting and transporting fabric during the treatment process. The axially displaceable roller is oscillated back and forth transverse to the path of fabric movement during the treatment process without requiring substantial movement of supporting structural elements.
According to another aspect of the invention, a jig dyeing machine is provided which is adapted for use in either atmospheric or high pressure/temperature conditions and in which cooperating rollers which take up and let off the fabric during the treatment process may be carried within self lubricating and self aligning bearings mounted at either end of the rollers thereby eliminating any need for lubrication devices.